Benzene dicarboxylic acid derivatives



ing of the 4, 5, and 6 2,808,433 Patented Oct. 1, 1957 2,808,433 BENZENE DICARBOXYLIC ACID DERIVATIVES William S. Struve, Carneys Point, N. 1., assignor to E. ll. du Pont de Nemours and Company, Wilmington, Del. a corporation of Delaware N Drawing. Application August 21, 1953, Serial No. 375,834

7 Claims. (Cl. 260518) This invention relates to new benzene dicarboxylic acid derivatives that may be diazotized and coupled to produce azo dyes. It relates preferably to such new derivatives of terephthalic acid.

It is an object of this invention to prepare a new series of benzene dicarboxylic acid derivatives having the struc- 0 tural formula CONHR wherein R is a nucleus from the group consisting of benzene, naphthalene and substituted benzene and naphthalene nuclei and wherein the substituents of the substituted benzene and naphthalene nuclei are taken from the class consisting of alkyl radicals of 1 to 6 carbon atoms, alkoxy radicals of 1 m6 carbon atoms, chlorine, bromine and nitro radicals, and the CONHR group may be in a position with respect to the carboxy group consistpositions, preferably in the 4 position. 7

This new series of benzene dicarboxylic acid derivatives may be diazotized and coupled to produce azo dyes. For example, it may be diazotized and coupled to 3-hydroxy-2- naphthoic acid'to produce an azo dye and, if desired, reacted with a metal compound such as a manganese compound to produce as an insoluble pigment the manganese salt of the azo dye. Such new dyes and pigments are described and claimed in copending application Serial No. 375,835, filed August 21, 1953.

The new benzene dicarboxylic acid derivatives of this invention may be produced by several alternative methods from commercially available materials using conventional reactions of organic syntheses. .Any of the three known benzene dicarboxylic acids may be used as starting materials, i. e.,

(1) phthalic acid,

COOH

2 2) isophthalic acid,

0 O OH C O OH (3) terephthalic acid, 10 c 0 0H the latter being preferred.

Using terephthalic acid as the starting material, a number of possible routes for the synthesis of the new dicarboxylic acid derivatives of this invention are shown structurally as follows:

COOH COOH COOCH; 0000113 N02 NO: NO:

OOH OOH OOOCH: OOH

CIIOOCH: COOCH: OOOH N02 N02 NC:

001 ONH\ CONH\ 40 l CO OH O 0 00113 NH: NHz

JJONH\ ONH\ C O OH ('30 Cl OOH 0C1 00 OH CO OH NO2 NH! -O ONH The following examples describe several processes for the production of the new compounds of this invention.

Example I 'A mixture of 80 grams of 2-nitroterephthalicacid 1- methyl ester (made by nitration of terephthalic acid, methylation and partial hydrolysis, as. described 'by Wegscheider, Monatschefte fiir Chemie, 23,411 (1902)), 800 cc. of toluene, 107 grams of thionyl chloride and'2 dropsof pyridine was heated at 90 C.--and held*for four hours after a clear solution was obtained. The mixture Wasco'ncentrated to half volume by distillation under reduced pressureJkeeping the p'ot'temperature'at'30-40 C. Then a solution of 76.5 grams of o-toluidine in 200 cc. of toluene was added below 40 C. and the charge heated at 40-50- C;for two hours. Ice and 54cc. of 37% "hydrochloric acid was added arid the solid was-filtered off, washed with water, and dried, giving 104 grams of colorless product;*'M. P. 137-140 C. This product was identified as:

2'-methy1=2-nitroterephthalanillc acid methyl ester CONH- L:

-washed, and dried, giving 73 grams; M. P. 211-214 C.

After recrystallization from dilute methanol the product melted at 214216 C., resolidifie'd and melted-'at231 C. This product was identified as:

2'-methyl-2-nitro-terephthalanilic acid AONH 4 Ninety grams of this product was dissolved in 900--cc.-of water-by'means-of 30% NaOI-Isolution-and the mixture was adjusted so that it was alkaline to Brilliant Yellow but not alkaline to phenolphthalein. The mass was hydrogenated at 7080 C. at 400-500 pounds pressure in the presence of 4.5 grams of palladium-charcoal catalyst. The catalyst was filtered off and the filtrate was acidified with hydrochloric acid. The product was filtered oif, washed, and dried, giving 76 grams; M. P. 221-224" C. This :product was identified as:

2-amino-2-methy1terephthalanilic acid coon To a slurry of 250 grams of Z-nitroterephthalic acid I-methyl ester in 500 cc. of water was added dropwise with stirring -1l5 CCrQf 30% -NaOH solution'diluted to l300'cc. The filtered solution was hydrogenated at 40 .C. at 200300,pounds pressure int-he presence of 10 grams of palladium-charcoal catalyst. Then, 22 grams or sodium carbonate was adde'dand the reaction mass was filtered to remove the catalyst. To the solution was added grams of ethyl chlorocarbonate and'the mass was stirred at room temperature for three hours, keeping the reaction alkaline by additions of sodium carbonate. At the end of the first hours stirring, an additional 14 grams of ethyl chlorocarbonate was added. The clarified reaction-mass was acidified and the product was filtered ofl, washed and dried. The dried material was slurried hot in 2700 cc. of methanol and filtered from the cooled mass giving 164 gra'ms of a product having a M. P. of 233-235 C. This product was identified as:

2-carhethoxyaminoterephthalic acid-l-methyl ester 0 O O CH:

LCOOH -'Ainixture of-grams of the above product, 1500 cc. of toluene,.4"drops-' of pyridine and 120 cc. of thionyl 'chloridewas'heated'at 90-C.-for sevenhours. Then, the mass was concentrated to half volume by distillation 7 under reduced -pressure, keeping the pot temperature at 30-40? C. A mixture of 171' grams of S-nitro-o-toluidine 'in 2100 cc.'of toluene was added and the mixture heated --at40-'5( C. Iceand 75 cc: of'37% hydrochloric-acid were--added-and the-solid was filtered oft,'washed first with-water andthen 'withmethanol and dried, giving 172 grams; M.'P.'231'-232 C. This product was-identified -2-carbethoxyamino'24nethv1-5-nitroterephthala.ni1ic acid. a methyl ester .COOCHa N HO Q0 0211;;

NO: -O

and the clarified mass was acidified with 130 cc. of 37% 134-138 C. after one recrystallization from methanol. hydrochloric acid and the precipitated product was fil- This product was identified as:

tered off, washed and dried, giving 123 grams of tan th 1 it hthal nu t solid; M. P. 250-277 C. After slurrying several times me y n g a with hot methanol, the product melted at 284-292 C.

This product was identified as:

N 02 2-am1no-2-mefl1yl-5-nitroterephthalantltc acid N 10 NHCO A mixture of 112 grams of the above compound, 84 cc. oNH- of 5 N sodium hydroxide solution and 560 cc. of water was boiled for ten minutes and the clarified solution was 0H9 acidified. The precipitated product was filtered 01f, Clear identification of the parent member (Z-aminoag: gg l gxs gfi ifi 247 terephthalanilic acid) was established in the following g p manner; G-nitroisophthalanilic acid The Z-amino-terephthalanilic acid was titrated with 0 011 alkali to give the neutral equivalent value of 253.5 compared with the theoretical equivalent of 256. Again, a NO, sample of this compound was titrated with sodium nitrite in acid solution to give the nitrite value, a stand- 'ard method of analysis for diazotizable amines. 97.75% NHC'O of the theoretical amount of nitrite was consumed.

The compound 2-amino-2',4-dimethoxy-5'-chloro terephthalanilic acid was analyzed for chlorine, giving a chlorine content of 10.05% compared to the theoretical of water and 36.3 cc. of 30% sodium hydroxide solution The following derivatives of terephthalanihc acid, charwas hydrogenated in the Presence of 5 grams of Dab acterized by melting Point P been Prepared and ladium charc'oal catalyst at 70-80 C. and at 400-500 identified y the methods desmbed below: pound pressure. The catalyst was filtered OE and the A solution of 100 grams of this compound in 1000 cc.

solution acidified, giving 83 grams of product; M. P. m Ester m Acid Amino Acid 279-281 C. This product was identified as:

COOCH; oooH OOOH v B-aminoisophthalanillc acid COOH Amine Used N02 N02 NH: 40

R N Ha 00mm ooNHR ONHR NHCO 0. 0. "0. 140-143 193-195. 5 202-204. 5 137-140 214-215 223-225. 5 d 5 *ii? iitiiii -Tolui 1ne 1 5.5- -Anisidine a gti Example IV 1 1 DAD Blame 1 206 238-240 The methyl ester, n1tro acld and amino ac1d derivag jggg tives of the compound resulting from the replacing of 235-237 252-2535 aniline in Example III with 2,4-dimethoxy-5-chloraniline 3 gggjgg' were prepared and identified. These derivatives had the 200-201' 249-252 following melting points: 242-244 258-260 a 244-240 279.5-281 h l M.7P. C. Met y ester 1 8-179 2 25 .5-2 241 5 42 5 7 Nitro acld 266-268 242. 5-244 255-257 2255-3555 6 Ammo acld 257 259 30- 211-212. 5 227-232 0 Example V Sodium 6-aminophthalanilate was prepared by catalytic Example 111 hydrogenation of the sodium salt of 6-nitrophthalanilic A mixture of 100 grams of 4-nitroisophthalic acid-3- acld- The free ac1dW as nt1sP1atedmethyl ester (Axer, Monatshefte fiir Chemie, 41, 151 The products of thls lnvention are useful as dlazo com- 1920 1000 cc. of toluene, 2 drops of pyridine and s0 Ponents 1n the Preparaflon of azo dyes Wlth unusually cc. of thionyl chloride was heated at 90 C. for seven good P P P 0f -f es d IBtf-dOm from bleed. hours and the mass was concentrated to about 500 cc. by V Rfiference 1n the speclficatlon and 01341115 P P distillation under reduced pressure, keeping the pot tem- P0111011s and percentages, 11111655 othel'wlse p f perature below 40 C. Then a solution of 85 grams of refefs P9 PYQPOYUOIIS, and Percentages y W ight. aniline in 500 cc. of toluene was added over a one-half slnce It is OQVIOUS that y changes 31151 of ficatlons h i d b l 40 c, d h charge was heated at can be made in the above-described details w1thout de- 40-50 C. for two hours. Ice and cc. of concentrated PaTtillg from the nature and Spirit of the invention, it is HCl were added and the solid was filtered off, washed to be understood that the invention is not to be limited well with water and dried, giving 114 grams; M. P. 75 to said details except as set forth in the appended claims,

7. I s aw 1. A compound having the formula: I

wherein R is a nucleus from the. group consisting of benzene, naphthalene and substituted benzene and naphthalene nuclei and wherein the substituents of the substituted benzene and naphthalene nuclei are takenfrom he lass consi n 'n a yli adit l o 1 R16 c rbon atoms, alkoxy radicals of 1 to 6 carbon atoms, chlorine, bromine and nitro radicals, andthe -CONHR group may be ina position, with respect to the carboxy group, consisting of the 4; 5 and 6 positions.

2. A compound having the formula:

(IDOOH NHa CONHR 8 wher in R s; a i. .9 us -r m. h rout; cons ing of en ene, naphth len an u ti ntedlben'z ne nd naphthalene 1,L ,C1,ei and whereinthe substituents of-the s ubs tut d. benzene nd nln ha ne uclei-a c ken rom the class consisting ofifalkyl radicalsof I to 6 carbon atoms, alkoxy radicals of Ito -6 carbon .atoms chlorine; bromineandnitro radicals. v I

3. 2-amin'o-2' methy-l terephthalanilic acid;

4. 2 amino 2,4' dimethoXyJ- S' chloro 'terephthalanalic acid.

5. 6-aminoisophtha1anilic acid;

6. 2-amino-2'-methyl-5-nitroterephthalanilic acid.

7. Z-amino-terephthalanilic acid.

References Cited in the fi-le of this patent UNITED STATES PATENTS Rose Aug. 3, 1937 Schumacher et a1. May 23, 1939 

1. A COMPOUND HAVING THE FORMULA: 